Python: Fix reachability-related test failures

Author: tausbn

python/ql/lib/semmle/python/dataflow/old/Implementation.qll

@@ -256,7 +256,7 @@ class TaintTrackingImplementation extends string instanceof TaintTracking::Confi
     TaintKind kind, string edgeLabel
   ) {
     this.unprunedStep(src, node, context, path, kind, edgeLabel) and
-    node.getBasicBlock().likelyReachable() and
+    node.getBasicBlock().(BasicBlockWithPointsTo).likelyReachable() and
     not super.isBarrier(node) and
     (
       not path = TNoAttribute()
@@ -684,7 +684,9 @@ private class EssaTaintTracking extends string instanceof TaintTracking::Configu
     TaintTrackingNode src, PhiFunction defn, TaintTrackingContext context, AttributePath path,
     TaintKind kind
   ) {
-    exists(DataFlow::Node srcnode, BasicBlock pred, EssaVariable predvar, DataFlow::Node phi |
+    exists(
+      DataFlow::Node srcnode, BasicBlockWithPointsTo pred, EssaVariable predvar, DataFlow::Node phi
+    |
       src = TTaintTrackingNode_(srcnode, context, path, kind, this) and
       defn = phi.asVariable().getDefinition() and
       predvar = defn.getInput(pred) and

python/ql/src/Functions/ConsistentReturns.ql

@@ -12,6 +12,7 @@
  */
 
 import python
+private import LegacyPointsTo
 
 predicate explicitly_returns_non_none(Function func) {
   exists(Return return |
@@ -21,7 +22,7 @@ predicate explicitly_returns_non_none(Function func) {
 }
 
 predicate has_implicit_return(Function func) {
-  exists(ControlFlowNode fallthru |
+  exists(ControlFlowNodeWithPointsTo fallthru |
     fallthru = func.getFallthroughNode() and not fallthru.unlikelyReachable()
   )
   or